1. Field of the Invention
The present invention relates generally to methods and apparatus for accomplishing selective production fluid testing of wells to provide a production profile identifying the amount or percentage of oil, water, and gas constituents of the production fluid flowing from wells. More particularly, the present invention is particularly applicable to selective production fluid testing of multilateral branch wells to provide a nearly real-time oil, water, and gas production profile that is available to well operators while the coiled tubing equipment is available at the wellsite, to enable a well operator to make conclusive decisions as to remedial well servicing activities, such as optimal perforation or production zone shutoff when the production profile indicates the presence of excessive water or gas in the well flow.
2. Description of Related Art
When currently used horizontal production logging is being conducted, it has been determined that the acquired logging data is not always conclusive for optimal remedial action. For example, well production can be unstable at the time of logging, thus rendering the logging data quantitatively uninterpretable. Also, the validity of results from existing horizontal production logging services is heavily dependent on the skill and experience of the wireline engineer, particularly in providing an oil production profile. Further, it is not yet possible to determine gas flow rates in horizontal multi-phasic conditions with production logging sensors.
Other well conditions can significantly alter well production profile analyses. For example, sealing one perforation can change the dynamics of well production, so the flow rate profile determined by production logging may not be predictive of the results of remedial action.
Well owners and operators have a present need to take optimal and quick remedial action on cased or open hole laterals of wells when there is an indication of excessive water or gas production. According to present day well logging technology, the well production operator does not become aware of the results of horizontal well production logging until after a detailed and comprehensive interpretation of sensor data has been performed off-site and after the coiled tubing unit has moved off location. There is thus a need for real-time determination of oil, water, and gas production during horizontal production logging services so that the operator of the well can instantly learn of the production characteristics of the well or any particular perforated zone or branch of the well and has the opportunity to take immediate corrective or remedial action while the well servicing equipment is at the wellsite and available for additional logging procedures. With a real-time determination of optimal plug placement and the coiled tubing unit remaining available at the wellsite, the well operator is able to make conclusive decisions as to optimal perforation shutoff, with the coiled tubing unit ready to provide remedial activity for the well.